1. Field of the Invention
This invention relates to an image processing method for an image processing apparatus that reads an image of a manuscript and processes the read image of the manuscript.
2. Description of the Related Art
A technique of embedding a watermark or the like in advance into a document image the duplication of which is not permitted, and thus prohibiting the duplication of the image itself, or a technique of embedding data related to the contents of a document and thus preventing falsification of the data and the contents of the document of the corresponding part, is becoming generally popularized.
However, though a method of embedding information of copyright owner and prohibition of duplication into a part that constitutes an entire target image for copyright protection and thus limiting changes and downloading of a file is employed mainly with respect to soft copies in network distribution, for an image that is very likely to be misused after duplication such as a stamp or sign that is additionally written after making a hard copy, it is difficult to embed data indicating prohibition of duplication into the image in advance.
As described above, stamps and signatures vary in shape and size, and detection of them is difficult by using a method like pattern matching. Also, unless a target image is changed to a predetermined color in printing from a monochrome read image, or unless an image is recorded after its original image is magnified at an extremely large or small magnification, an image equivalent to the target image can be acquired by magnifying again to the size of the original image. Therefore, compared with other specific images, duplication and use of them can be easily carried out. Thus, there is a problem that the possibility of misuse is high.